1. Field of the Invention
The present invention is related to an apparatus for controlling hydraulic pressure and can be used, for example, for a transmission mechanism for a vehicle such as an automatic transmission or a continuously variable transmission.
2. Related Art
Transmission mechanisms used for automobiles include a transmission called an automatic transmission or a continuously variable transmission. This transmission mechanism has actuators such as a hydraulic pressure type cylinder, valve, and accumulator, and a solenoid valve, and controls a transmission gear ratio by these hydraulic pressure type actuators and the solenoid valve. The transmission mechanism uses hydraulic pressure as fluid. Further, the transmission mechanism is constituted by a transmission unit, a solenoid valve unit, and an electric control unit (ECU).
German Patent No. DE19955603C1 discloses a hydraulic control module in which an ECU and an actuator are integrally arranged.
However, an transmission mechanism in the related art presents such a problem that it has a large number of components, increases in size and requires a large number of manufacturing man-hours.